HP has announced that they will open source the AdvFS under the second version of the GPL. AdvFS is a mid-90's file system that is used by the Tru64 UNIX operating system. The Wikipedia page on AdvFS provides the necessary background information and feature set of the AdvFS file system.

In case its not clear, this is a GPLv2 technology release, not an actual port to Linux. We're hoping that the code and documentation will be helpful in the development of new file systems for Linux that will provide similar capabilities, and perhaps used to make tweaks to existing file systems. We'll get the tests posted soon.

But in http://advfs.sourceforge.net/ you can read that they're releasing two generations of advfs source code: "The first generation is the version that is currently shipping on Tru64 which represents a well tested enterprise quality file system that has been deployed worldwide for many years. The second generation is a port [to Linux] that was completed a few years ago but never productized."

So it's not clear that they're doing anything with this code. For now, they've just packed up the source and put it in a website. But how useful would be to release this code if they're not planning to port it to linux?

I've downloaded this stuff and AdvFS v2 is actually a port to HP-UX, not Linux. There aren't any makefiles, and though the userland part may compile quite easily under Linux (not tested though) the kernel part is a tougher one...